Finishing of preformed parts such as metal castings has been done by vibrating the parts while submerged in an abrasive media, which is generally known as "vibratory finishing". The various vibratory finishing processes have been used to clean foundry mold sand and other materials from the surfaces of parts, remove casting fins, remove machining burrs, remove rust and other oxides and polish the exterior as well as interior surfaces of the parts. Finishing the internal surfaces of parts is more difficult than finishing the external surfaces and more time consuming.
Vibratory finishing has been carried out by using resonant vibration, which is usually at a high frequency vibration, as exemplified by U.S. Pat. No. 3,581,440 to McKinney, and by lower frequency, nonresonant vibration, as exemplified by U.S. Pat. No. 4,581,853 to Marcus. The disclosures of these patents are incorporated herein by reference.
The resonant vibratory finishing is efficient in a limited range of operation which largely depends on the characteristics of the resonating member in the equipment and on the combination thereof with the mass of the parts attached to the resonating member. The equipment is usually large and heavy compared to the parts being finished, requires heavy duty motors to power the resonating member and has little flexibility of operating ranges.
The nonresonant vibratory finishing is more flexible in its range of operation and in the types and sizes of parts which can be finished on a given piece of equipment. The lower frequency operation is quieter, has lower power requirements and can use lighter weight apparatus components. In addition, the free-moving vibrating member provides more flexibility and productivity for attaching parts at more points along the vibrating member.
In the above processes it is frequently desired to enhance the vibratory finishing by not only vibrating the parts in the finishing media, but to also vibrate the media as well by vibrating the container holding the media.
It is an object of this invention to provide more efficient apparatus and processes for finishing of parts.
It is another object of this invention to provide vibratory finishing apparatus which is smaller, more flexible and adaptable in use and has lower power requirements for finishing given parts.
It is another object of this invention to provide vibratory finishing processes which are more efficient, quieter in operation and provide faster finishing of given parts.
Other objects and advantages of the present invention will be apparent to those skilled in the art.